Inhalation of NO₂and Blood Borne Cancer Cell Spread to the Lungs

Abstract

An experimental model was designed where the frequency of blood-borne cancer cell metastases to the lungs of animals was used as an indicator to detect adverse effects of inhaled nitrogen dioxide (NO2). Animals were exposed to air containing 0.40 +/- 0.05 ppm or 0.80 +/- 0.05 ppm of NO2. After the appropriate exposure periods, the animals were infused intravenously with B16 mouse melanoma cells. At 3 wk post-infusion the animals were killed and the lungs were examined for melanoma nodule development. The lungs of the NO2-exposed animals contained a significantly higher number of melanoma nodules than the lungs of control animals (P less than .0025). These results indicate that inhalation of ambient or near ambient levels of NO2 influences the metastasis of blood-borne cancer cells. This raises the possibility that similar events may occur in the human population.

Enhanced NO2 selectivity of hybrid poly(3-hexylthiophene): ZnO-nanowire thin films

“…1,2 This has propelled a significant research on the development of sensors that can detect very small concentration ͑ppm level͒ of NO 2 . 1,2 This has propelled a significant research on the development of sensors that can detect very small concentration ͑ppm level͒ of NO 2 .…”

Airborne cadmium and carcinogenesis of the respiratory tract.

“…Likewise, there are no data to support an interaction, possibly synergism, between inhaled cadmium and oxidants on the basis of a suggested formation of nitrosamine in the organism after nitrogen dioxide inhalation (103). The finding of a facilitation of metastasis of existing tumors during long-term lowlevel nitrogen dioxide exposure could be another variant in the interaction of an environmental pollutant with a carcinogen like cadmium (86). Certainly, more research is needed to elucidate the important questions about the combined effects of other pollutants and cadmium on the induction of lung cancer.…”

Ambient Air Quality and Human Health: Current Concepts, Part 2

“…However, there is little evidence to suggest that community air pollution is a significant cause of cancer except in unusual cases of point-source emissions, such as smelters, where known carcinogens, particularly arsenic, may play a causal role in locally elevated risks for lung cancer. There is a strong suggestion in the experimental literature that exposure to oxidant air pollution may increase the frequency of metastases to the lung of established cancers (57,58). However, the evidence for a direct connection between lung cancer and ambient urban air pollution is weak and limited to situations of appallingly bad air quality (59).…”